763 Jock, I sincerely hope that you won’t need it! If you ever need it then you will unfortunately find out that you won’t be getting 20 x £525.
The calculator on the GOV.UK website assumes that your employer is still operating. Once you are made redundant due to your employer going bust, several other caps are introduced and you get nowhere near the amount of 20 x £525. Unfortunately I found out the hard way when Monarch went bust.